When it is cold, your body shivers to stay warm, which ressembles some of the effects of exercise, according to researchers at the National Institutes of Health.
During exercise, your muscles produce the hormone irisin, which stimulates an increase in brown fat in the body’s tissues. Brown fat, which is dispersed within the body’s white fat stores, feeds off food or white fat to produce energy. It is considered to be a “good” fat for the body.
In a new study published in Cell Metabolism, researchers observed a group of 10 healthy volunteers while they exercised at maximal aerobic capacity, measuring their energy expenditure and taking blood samples. They then had the subjects rest in bed covered with cooling blankets and lowered the blanket temperature to 53.6 F, which, for the majority of participants, triggered a shivering response to warm the body.
Overall, the researchers found that the levels of irisin produced when study participants exercised were comparable to those seen when participants were shivering.
These findings allowed researchers to better understand how irisin production occurs in the body and could someday lead to pharmacological substances capable of stimulating irisin production, Fox News reports.
Researcher Francesco S. Celi, chair of the division of endocrinology and metabolism at






